Human teeth are stained by adhesion of various staining substances on their surfaces as well as calculus and plaque, and the gloss of teeth also decreases. These staining and a decrease in gloss are not cosmetically desirable, and various means to whiten teeth are developed.
With such a background, for example, it has been known that phytic acid has activities such as removal of tobacco tar, a suppressive effect against calculus and stabilization of stannous fluoride, and a dentifrice containing phytic acid has been reported (Patent Document 1). In addition, an oral composition in which zeolite is blended (Patent Document 2), and a dentifrice composition in which particles having specific collapse strength (Patent Document 3) and the like are blended, in addition to phytic acid, have been also reported. Furthermore, the present applicant reported that conventional whiteners or abrasives cannot sufficiently remove minute solid matters with the height of less than 1 μm which adhered to a tooth surface, but use of a composition which contains phytic acid and no polyvalent cation and has pH adjusted to a certain range can remove minute solid matters which adhere to a tooth surface, and whiten the teeth and impart gloss to the teeth (Patent Document 4).